[Methodology and application of precipitation isoscapes of stable hydrogen and oxygen isotopes]

The precipitation isoscapes of stable hydrogen and oxygen isotopes combine isotope tracing technology with spatial perspective, which are useful to examine the source and sink of water in different regions, to understand the isotope fractionation in atmospheric, hydrological and ecological processes, and to reveal the pattern, process, and regime of water cycle on the earth's surface. We reviewed the development of database and methodo-logy for precipitation isoscape mapping, summarized the application fields of precipitation isoscape, and put forward the key research directions in the future. At present, the main methods in mapping precipitation isoscapes include spatial interpolation, dynamic simulation, and artificial intelligence. In particular, the first two methods have been widely used. The applications of precipitation isoscapes can be classified into four fields including atmospheric water cycle, watershed hydrological process, animal and plant traceability, and water resources management. The future works should focus on the compilation of observed isotope data as well as the data evaluation of spatiotemporal representativeness, and pay more attention to develop the long-term products and quantitatively assess the spatial connection among various water types.